不同热处理温度下LaFe_(11.6)Si_(1.4)合金的相和组织结构

Research of Phase and Structure of LaFe_(11.6)Si_(1.4) Alloys under Different Heat Treatment Temperatures

研究了经不同温度热处理后的LaFe11.6Si1.4合金的相和组织结构,并探究其相变机理.铸态LaFe11.6Si1.4合金在高温热处理时经历包析反应和包晶反应.在低于1423K左右时,铸态LaFe11.6Si1.4合金发生Fe（Si）＋LaFeSi→1∶13固固包析反应;在1423~1593K,发生Fe（Si）＋LaFeSi→1∶13固液包晶反应;在1593~1739K,已形成的1∶13相熔化,合金处于固相Fe和液相两相区.基于相变热力学及动力学的因素,铸态合金在1523K附近具有最大的包晶反应驱动力,LaFe11.6Si1.4合金热处理5小时后,合金1∶13相含量最高.

A research is made of the phase and structure of LaFe11.6Si1.4alloys undergoing a heat treatment at different temperatures,and to explore the mechanism of the phase transition.The LaFe11.6Si1.4cast alloys undergoes the peritectoid reactions and peritectic reaction under high temperature heat treatment.At the temperatures of less than about 1423 K,the cast alloy undergoes LaFe11.6Si1.4Fe（Si）＋ LaFeSi→ 1∶13Solid Solid peritectoid reaction;at the temperatures of 1423~1593K,it undergoes Fe（Si）＋ LaFeSi→ 1∶ 13solid-liquid peritectic reaction;while in temperatures of 1593~1739K,1∶13has formed a molten phase,Fe alloys are found in a solid/liquid two-phase state.Based on factors of phase transition thermodynamics and kinetic phase transition,cast alloy at 1523 Kpossesses a maximum peritectic reaction driving force,after 5hours of heat treatment of LaFe11.6Si1.4alloy,the 1∶13alloy is of the highest phase content.